The invention relates to cable pullers.
Cable pullers are used to wind a cable about a drum. The cable end can be attached to an item in order to lift the item or the puller can be used to stretch the cable. It is known in the art to have cable pullers that are powered or operated by hand. To gain leverage in order to lift or pull heavy objects, on the order of three to four tons, existing cable pullers have a straight line telescoping handle. This arrangement creates several problems including: the operator having a difficult time guiding the load due to the distance of the handle from the drum; the impracticality of operating the device in a confined space; and the inherent safety risk of the lever inadvertently striking the operator.
U.S. Pat. No. 4,199,134 (Kerber et al) discloses a portable winch having a ratchet wheel and an actuator. The actuator carries a pawl and a grip. The actuator member is connected at the center of the ratchet wheel so that rotation of the actuation member causes the pawl to engage the ratchet wheel.
U.S. Pat. No. 4,723,757 (Steinman et al) discloses a portable winch having a ratchet wheel and an actuation member 16 provided with a grip. This actuation member is attached at the center of the ratchet wheel.
U.S. Pat. No. 2,658,723 (Coffing) discloses a hoist having a ratchet wheel and an actuation member carrying a pawl. A linkage connected to the center wheel spaces the actuation member from the wheel.
U.S. Pat. No. 1,823,760 (Pierce) discloses a jack having a ratchet wheel and an actuation member having a pawl. A handle connects to the end of the actuation member.
There is a need in the art for a cable puller having a handle providing leverage to create a large pulling force with a minimal amount of force applied by the operator.
It is another object of the invention to provide a cable puller having a compound handle that increases leverage and magnifies the force applied by the operator.
It is another object of the invention to provide a portable, compact cable puller that can be easily transported and used to generate a large pulling force.
It is another object of the invention to provide a reliable cable puller that is both easy to use and inexpensive to manufacture.
These and other objects of the invention will be become apparent to one of ordinary skill in the art after reviewing the disclosure of the invention.
The cable puller, embodying the present invention, uses a compound handle to create great leverage in order to generate a large pulling force with a minimal amount of force applied by the operator. The pulling force can be used for such applications as lifting heavy objects. The cable puller could be used to hoist motors, shafts, gears, automobile engines, construction material, machinery and other heavy objects. The cable puller could also be used in the demolition of building structures, the erection of buildings and towers, straightening collision damage, opening railroad car doors, securing tent structures, stretching fence and wire, and tightening conveyor belts. In one embodiment, the handle creates a lever ratio of 65:1. In this instance, four tons can be lifted with an exertion of 123 lbs. of force by the operator.
The compound action of the handle is similar to the low gear on a bicycle in that it reduces the operator""s effort but causes the load to ascend and descend at a slower rate. The slower movement of the load reduces the risk to the operator as it is easier to control.
The compound handle is formed by a driven member that engages and rotates the ratchet wheel. A cable is taken up by the wheel in order to move objects. The driven member is connected to a driving member by a connection member. The driving member has a handle grasped by the user and pivoted in order to cause the driving motion of the ratchet wheel.